Safety lock



Dec. 16, 1952 Iv OSTADAL 2,621,951

SAFETY LOCK Filed Jan. ll, 1949 Patented Dec. 16, 1952 UNITED STATES P'EET OFFICE Application January 11, 1949, Serial No. 70,325 In Czechoslovakia October 29, 1948 Claims.

For locking the doors of bath-rooms, waterclosets and the like use 'is made at present of dor locks constructed in such a manner that by turning the inner handle in reverse direction, usually by an angle of 90 degrees, the person who occupies the room is secured against opening of the door by another person using lthe outer handle. Further on, the known type of safety locks are used in which by reverse turning of the outer' handle it is possible, when required, to unlock the door which has been locked by means of the inner lock and to open the door by depressing the outer handle, while with the inner handle unlocked it is possible, by the said turning movement of the outer handle, to place the lock in such a condition as to make impossible the opening of the door by means of the inner handle. The last mentioned provision makes impossible the access of unauthorised persons e. g. from a bathroom to the interior 0f the dat, if the window of the bath-room or the like is easily accessible from outside the house.

However, the safety locks of the vkind specified are relatively complicated and cumbersome, 'consist of a large number of component parts, and when a certain degree of wear has taken place they become ineiilcient.

The safety lock in accordance with the present invention complies reliably and permanently'with all the aforementionedrequirements Vand in addition is extremely simple and cheap in respect both of the material used and the room required for mounting the same on a door.

The invention resides in an arrangement in which the bolt of the safety lock is adapted to be controlled and locked independently either by the outer or by the inner handle, the said bolt being provided in its inner extended part with a single aperture in which operates a finger of the tumbler of only one of the two handles while a projection and a stud of `the second 'handle co-operate only with projections on .the vouter periphery of the said extended portion of 'the bolt. An important simplication 'as compared Figure 2 is a cross-sectional View of the lock taken along the line A-A of Figure 1.

The lock in accordance with the present invention has a casing `I and a front plate '2 mounted on the same, `the end'of the bolt 3 passing through an opening provided in the plate 2. For opening the door, the bolt 3 is retracted in the direction of the arrow B until the extended inner part 3 of the bolt abuts against the back wall of the casing shown in Figure 1 the bottom of the said inner part engaging and sliding upon a stud 4 fastened inthe walls of the casing. A spring 5 urges the bolt towards its extreme right hand position as viewed in Figure 1, i. e. outwardly of the casing to its latched position.

The rearwardly extended plate portion of the bolt 3 is provided with an aperture 6 through which passes a tumbler 'I fastened on a squared shank portion Ia of the upper handle i8, this handle being usually on the outer side of the door leading to the room and usually occupying a horizontal position, as shown, in the latched position of the bolt. The tumbler I is provided with a nger 8 movable within the aperture 6, and above the upper face plane yof the inner part of the bolt the tumbler is provided with another finger 9, as shown in Figure l. At nearly diametrically opposite sides with respect ,to the above mentioned fingers, the tumbler is provided with flat surfaces la, Ib which are parallel to the axis of rotation of the tumbler and are engaged in turn by a spring I0. The underside of the inner part 3 of the bolt is engaged '.by the lower tumbler I I which is fastened on a squared shank portion I9a of the lower handle I9, this handle being usually the one on the inner side o'f the door leading to the room and usually occupying a horizontal position, as shown, in the latched position ofthe bolt. 'This last mentioned tumbler is provided with two projections .I2 and I3, of which the iirst coi-operates with Aa corresponding portion of the bolt `3 andthe second co-operates with the nger 9 of the tumbler l. The tumbler I I carries further a stud I4 adapted to co-operate with the bolt. The tumbler II vis also provided with two ilat surfaces Ha, Hb .parallel to its axis of rotationand at right angles to each other, with which a spring 1.5 .is'adapted to engage in turn.

The drawing shows in full lines the component parts of the lock in the position which 4they occupy when the door may be opened in the usual way by depressing the outer or .theinner handle below its normal `horizontal .position thereby vrotating either the tumbler .'I or tumbler I I vcounterclockwise as viewed infie. 1. If the outer handle I8, that is the upper one as shown in the drawing, is depressed, the nger 8 which bears against the left side of the aperture 6 in the bolt inner part 3 will push the bolt to the left as viewed in Figure 1 until its outwardly projecting end portion is withdrawn into the corresponding opening so that the door may be opened. Upon release of the handle the spring l will return the tumbler 1 and with the same the handle itself to their original position, while the spring will move back the bolt 3.

Similarly, if the inner, that is the lower handle I9 is depressed, the projection l2 of the tumbler Il, which bears against one face of a depending toe portion I1 at the bottom of the bolt 3, will push the bolt to the left as viewed in Figure 1, and when the handle is released again the two members just mentioned are returned to their initial position under the action of the springs 5 and l5.

If a person enters the room and wishes to make impossible the opening of the door in the usual way from the outside, the inner handle i9 should be turned back in clockwise direction as viewed in Fig. 1 from its normal horizontal position to a vertical position. As a consequence, the tumbler Il will assume the position shown in dot and dash-lines in Figure 1. The stud I4 will assume the position I4' in which it engages in an adjacent recess formed in the opposite face of toe portion l1 of the bolt 3, while the shoulder I6 of the bolt will engage with the stud 4 whereby no further movement of the bolt 3 is possible if the upper handle I8 is depressed. The tumbler Il is retained in this position by the pressure exerted on its bottom flat face by the spring l5.

If with the lock fixed in the manner just described lit is required to open the door from the outside, the outer handle I8 should be turned about 90 degrees clockwise as viewed in Fig. 1

from its normal horizontal position. During the first part of this movement the finger will engage the projection i3 of the tumbler H, which projection occupies at that moment the position I3 shown in dot and dash-lines in Figure l, and then the finger 9 during its further movement will cause the tumbler Il to return to its initial position shown in full lines in Figure 1, the spring I5 also taking part in this operation. Thereupon the door may be opened by the usual movement of the upper handle i8.

On the contrary, when it is desired to look the door from the outside so as to prevent it being opened by means of the inner lower handle i9, the outer upper handle I8 is brought again to its above mentioned vertical position assuming of course that the lower handle Hl is in its horizontal position. In this case, the finger 8 of the upper tumbler 'l will assume the position 8 shown in dot and dash-lines in Figure 1 in which this finger prevents any movement of the bolt 3 and especially the shifting of the latter due to depression of the lower handle I9. Also when the outer handle I8 has been turned to its upright, locking position, the inner handle I9 and tumbler l I cannot be rotated clockwise to unlock the bolt for when handle i8 occupies an upright position finger 9 occupies its vertical, broken line position 9 in which the fiat underface of the toe portion thereof lies substantially in contact with an adjacent flat face Ic on tumbler l i thus locking the latter against rotation clockwise. Consequently when the bolt is locked in the latched position by the inner handle I9 it can be unlocked by the outer handle I8 but when so locked by the outer 4 handle it cannot be unlocked by the inner handle.

The invention is not limited to the embodiment described in the specification and illustrated ln the drawing, but this single example shows clearly that the construction of the lock is very simple and that with such a construction it is possible to save much room and material. Thus, very good results were obtained in practice with a lock in which the distance between the axes of the tumblers was as small as 35 millimeters and the largest dimension of the casing was millimeters.

What I claim is:

1. In a safety door lock, the combination comprising; a lock casing; a bolt slidable within said casing; said bolt being normally urged outwardly of said casing towards its latched position and including an apertured plate portion in a rear extension thereof; a first tumbler within said casing mounted for rotation in the apertured portion of said bolt and controlled by a handle on one side of said casing, said tumbler including first and second ngers, said first finger being rotatable into engagement with the inner periphery of the apertured portion thereof, said first finger being engaged with the rear part of said apertured portion upon rotation in one direction to retract said bolt and engaged with the fore part of said apertured portion upon rotation in the opposite direction to lock said bolt in the outward latched position; and a second tumbler within said casing mounted for rotation outside of the outer periphery of the rear extension of said bolt and controlled by a second handle on the opposite side of said casing, said second tumbler including a first portion movable upon rotation of the tumbler in one direction into engagement with a portion of said outer periphery eiective to lock said bolt in the outward latched position, a second portion engaging another portion of said outer periphery upon rotation of said second tumbler in the opposite direction to retract said bolt and a third portion offset axially from said first and second portions which when said second tumbler occupies the bolt locking position is engageable by said second finger upon rotation of said rst tumbler in the said opposite direction to thereby rotate said second tumbler in the direction to disengage the said first portion thereof from the said outer periphery of the bolt.

2. A safety door loci: as defined in claim 1 wherein the said second finger on said first tumbler includes a flat adapted to substantially contact a flat on said second tumbler when said rst tumbler is rotated in said opposite direction thereby to prevent rotation of said second tumbler.

3. A safety door lock as defined in claim 2 wherein the said iirst portion on said second tumbler is constituted by a stud engageable with one face of a depending toe portion on the rear extension of said bolt, and the said second portion on said second tumbler is constituted by a projection engageable with the opposite face of said toe portion.

4. A safety door lock as defined in claim 3 wherein each of said tumblers is provided with a pair of at faces in parallel relation to the axis of tumbler rotation and substantially at right angles to each other and adapted to co-operate in succession with a spring retaining said tumbler in either of two predetermined positions.

5. A safety door lock as defined in claim 4 and which further includes a fixed stud extending transversely in said casing upon which the underfaee of the rearward extension of said bolt is seated for sliding movement, said underfaee including a shouldered portion engageable with said stud and providing a stop for the bolt when the latter has moved a predetermined distance in the forward latching direction.

VCLAV osTADL.

6 REFERENCES crrnn The following references are of record in the le of this patent:

5 UNITED STATES PATENTS Number Name Date Re. 22,230 Voight et al. Dec. 1, 1942 1,038,512 Anderson Sept. 17, 1912 2,174,958 Backhouse Oct. 3, 1939 

